1. Field of the Invention
The present invention relates to a member for electrophotography, a method for producing the same, and an image forming apparatus.
2. Description of the Related Art
In an electrophotographic image forming apparatus, members for electrophotography such as a charging member, a development member and a transfer member are used. As the member for electrophotography, a member for electrophotography having a support and an electro-conductive elastic layer which contains a polymer such as rubber on the support is used in some cases. In order to impart a prescribed electro-conductivity, for example, an electrical resistivity of 1×103 to 1×1010 Ω·cm, an ionic conductive material such as a quaternary ammonium salt may be contained in the elastic layer in some cases.
When a member for electrophotography having an elastic layer with electrical conductivity introduced with addition of an ionic conductive material is used for a long term, the ionic conductive material and low-molecular weight components of a polymer in the elastic layer bleed out on the surface of the member for electrophotography in some cases.
For example, when a member for electrophotography having an elastic layer including an ionic conductive material is used as charging member in contact with an object to be charged such as an electrophotographic photosensitive member for contact-charging, the ionic conductive material and low-molecular weight components of a polymer bleeding out from the elastic layer of the member for electrophotography adhere to the region of the object to be charged in contact with the member for electrophotography for a long period in some cases. The bleeding substances from the elastic layer adhere to the surface of the photosensitive member can be one cause of image defects such as white voids (blank spots) and density irregularities in an electrophotographic image.
In Japanese Patent No. 4365996, an electro-conductive roller is disclosed, having an electro-conductive support, an electro-conductive elastic layer including a quaternary ammonium salt compound of perchloric acid and a specific rubber, and a resistive layer. According to the description in the paragraph [0046] of Japanese Patent No. 4365996, the resistive layer is formed to prevent the adhesion to the electrophotographic photosensitive member and the pollution of the electrophotographic photosensitive member, and with use of a binder resin of synthetic resin such as a urethane resin from the viewpoints of flexibility and abrasion resistance, dispersed electro-conductive inorganic particles can be used to control the resistance. Further, according to the description in the same paragraph, the resistive layer can be mainly formed of urethane resin, in particular.
The present invention is directed to providing a member for electrophotography which can prevent the components in an elastic layer from moving to the surface, even when used for a long term, and a method for producing the same.
The present invention is also directed to providing an image forming apparatus capable of stably forming a high-quality electrophotographic image for a long period.